Cancer is a disease in which normal body cells are changed, becoming able to multiply without regard to normal cellular restraints and to invade and colonize areas of the body normally occupied by other cells. See B. Alberts et al., Molecular Biology of the Cell 1255–1294 (3d ed. 1994). According to the American Cancer Society, one-half of all American men and one-third of all American women will at some point in their lives develop cancer.
Due to the ability of cancer cells to spread and rapidly proliferate, it is difficult to treat cancer patients by attempting to selectively kill cancerous cells. Some have compared the difficulty of this task to the difficulty of completely ridding a garden of weeds. As with weeds, if only a few cancer cells are left untouched by treatment, they may again spread throughout the body, causing a recurrence of the disease. Current treatments for cancer include surgery and therapies using chemicals and radiation. The effectiveness of these treatments is often limited, however, since cancer cells that have spread from the original tumor site may be missed by surgery and radiation, and since chemical treatments which kill or disable cancer cells are often capable of causing similar damage to normal cells.
From the foregoing, it will be appreciated that there is a need in the art for novel cancer therapeutics which have higher efficacy, specificity, or reduced side effects.